Interactive Effects of Super Absorbent Polymer and Poultry Manure on Growth and Yield of Groundnut (Arachis hypogaea L.) under Field Conditions

Abstract

Super absorbent polymers (SAPs) have emerged as promising soil conditioners for improving water use efficiency in agriculture. SAPs are cross-linked hydrophilic polymers capable of absorbing and retaining water up to several hundred times their own weight and releasing it slowly to plant roots. The field experiment was conducted during the kharif seasons of 2023 and 2024 to assess the effects of graded levels of SAP and poultry manure (PM) applied in conjunction with the recommended dose of fertilisers (RDF) on growth, yield attributes, and yield of groundnut. The experiment was laid out in a randomised block design with ten treatments and three replications, comprising SAP at 0, 50, and 100 kg ha-¹ and poultry manure at 0, 3, and 6 t ha-¹. The results showed that the integrated application of SAP and poultry manure significantly improved growth and yield parameters across both seasons. The highest pooled plant height (61.10 cm), number of branches (8.59 plant-¹), dry matter accumulation (47.92 g plant-¹), and nodulation (63.80 nodules plant-¹) were recorded under 100% RDF + SAP 100% + PM 100%. Yield attributes such as kernels per pod (1.99) and 100-kernel weight (47.55 g) were also significantly enhanced under combined treatments. The maximum pooled kernel seed yield (2904.99 kg ha-¹) and harvest index (48.25%) were obtained with the integrated application of SAP and poultry manure, representing a substantial improvement over RDF alone and the control. Treatment effects were consistent across years, with slightly higher values observed during 2024. The improved performance under integrated treatments can be attributed to enhanced soil moisture retention, improved nutrient availability, and efficient assimilate partitioning. The study demonstrates that combining super absorbent polymer with poultry manure and RDF is an effective and sustainable strategy for enhancing groundnut productivity under moisture-limited conditions.